A trip to the Irvine service center today produced a good conversation with one of the tech reps. In short, I do quite a bit of BIF shooting (birds in flight) and focusing is a challenge when you have 6 cases in the 5DM3 menu (and 1DX) to choose from. I've read some articles that explain to be the holy grail in AF settings for BIFS but I have found them so-so. The service center had recommended this link which I thought to share with AI Servo users

Regarding this subject, I noticed that the eos iTr feature of the 1dx specifically says that the AF will be a bit slower if this feature is enabled. I haven't tried disabling it yet but I'm wondering if any other 1dx owners can weigh in on this subject. I've only used my 1dx "enabled" so far, but I since I shoot a lot of fast moving sports I'm now thinking that I should try disabling this feature....thoughts?

EvilTed

Better than the manual at explaining what the AF settings of the cameras are and the difference between them, but I have yet to find a tutorial on how to use AI Servo successfully

For one thing, without the red focus point lighting up, it's pretty much useless or how else does one know which point is in focus?

This tip:

"With “AI Servo AF” mode, the shooting startsfrom one AF frame that is optionally selected.So select one of any frames covering theposition where object capturing starts. Inaddition, it will be easy to continue trackingthence very convenient, if the same startposition is selected for Single Point AF andthen AF area is switched to 61 PointAutomatic Selection AF."

How does one switch both from Single Point AF to 61 Automatic Selection AF with one button click?

The 5DIII guidebook has been virtually copied from the 1DX guidebook and subsequently edited (carelessly). On page 5 of the 5DIII guidebook it gives an option "AF Status in viewfinder" which is available only in the 1DX and not on the 5DIII. I noticed a few more glitches but it is extremely helpful in understanding the AF.

you prgram the DOF button to toggle between 1 shot and servo its awesomealso I enable the 8 assist point focus mode this greatly helps with servo keeper rate

Actually, no - that doesn't do what ET wants. The DOF button toggle (I use the M.Fn2 button on the 1D X for that) switches the AF mode from One Shot to AI Servo but does not switch from single point selection to 61-point auto selection. The AF system will 'track across the frame' only if you're in 61-pt auto selection, but while that allows you to select a starting point if you're in AI Servo, if you're in One Shot the camera does the point selection. ET is looking for a way to switch from (One Shot + single AF point selection) to (AI Servo + 61-point auto selection) with a single button press.

ET, my solution to that issue is to have C2 as (One Shot + single AF point selection) and C3 as (AI Servo + 61-point auto selection) but otherwise with very similar settings (both Av mode, etc., although I have the min shutter set higher in C3). On the 1D X, I have the M.Fn button assigned to switch modes, so it's a one-button press to go into servo + 61-pt, and pressing that same button twice to go back to one-shot + manual select (on the 5DIII, it's a dial turn instead of a button press).

ET, my solution to that issue is to have C2 as (One Shot + single AF point selection) and C3 as (AI Servo + 61-point auto selection) but otherwise with very similar settings (both Av mode, etc., although I have the min shutter set higher in C3). On the 1D X, I have the M.Fn button assigned to switch modes, so it's a one-button press to go into servo + 61-pt, and pressing that same button twice to go back to one-shot + manual select (on the 5DIII, it's a dial turn instead of a button press).